I'm just trying to confirm what is supposed to be the compression ratio in my car. It's a 74. The heads have a 4 on the corner and a bump next to them. I know that the books all say the car has an 8 to 1 ratio. I'm just suspicious because I went to the strip last week and did 14:10s to 13:85s in 80 to 85 degree temperature.. The car is stock as far as I know except for a Holley and a pertronix adapter. That seems fast for a low compression motor. I'm collecting parts now for an update over the winter with a new timing chain, cam, and a lighter vavle train. I was also going to get some australian 2V heads, maybe in aluminum. I didn't know there was 4V open chamber heads. I thought that one of the big benefits to the australian heads was a bump of a couple points in compression. I'd hate to spring for the heads and then find out I already had closed chamber heads. Does that bump mean open chamber I guess is what I'm asking here. Does any one know know the CC of the open chamber heads vs. the closed chamber heads and what the resulting ratio is? Thanks as always for sharing the knowledge. Vince
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